The Seattle Mariners have been one of the league’s most active teams ahead of tonight’s 6 p.m. ET trade deadline, making two blockbuster deals with the Arizona Diamondbacks to acquire first baseman Josh Naylor and, last night, third baseman Eugenio Suárez. Naylor will be in the lineup tonight for the opener of a four-game series against the Texas Rangers, while Suárez likely won’t.
For the 9:40 p.m. ET first pitch, Seattle will start George Kirby and Texas will send Kumar Rocker to crest the hill.
Let’s break down this matchup with some odds and lines at DraftKings Sportsbook.
Texas Rangers at Seattle Mariners prediction, preview
The trades come at a good time for the contending Mariners, who have gone just 6-7 since the All-Star break with the league’s worst OPS as MVP contender Cal Raleigh has posted just a .240/.269/.420 slash line across that span. The decision to go all-in for Suárez was an interesting one, given that Seattle sits five games behind the Houston Astros for first in the AL West, tied with the Rangers. Texas is in much better form, having posted an 9-3 record to start the second half of the season, and its offense, which had been downright anemic for most of the season, has been a league-average unit across that span. The Rangers’ pitchers have been elite, posting a 2.69 ERA in the second half so far, behind only the surprising Miami Marlins.
Unfortunately for Texas, Rocker is not one of those elite pitchers. The third overall pick in the 2022 draft, Rocker’s rookie season has been rough, as he’s pitched to a 5.73 ERA and been worth negative-1.1 WAR. A demotion to the minors for the month of May helped him, as he’s posted a more solid 4.54 mark since then, but it’s clear that the 25-year-old hasn’t put his immense tools together just yet. His fastball frequently sits in the high 90s and he’s good at inducing ground balls, but he’s prone to giving up lots of hard hits, with just a fifth-percentile barrel rate. The Mariners have tended to lace the cover off the ball, which is to be expected from a team that rosters Raleigh, Randy Arozarena, Julio Rodríguez, and now Naylor and Suárez.
Kirby, after a tremendous start to his career, has cooled off significantly. He led all of the major leagues in strikeout-to-walk ratio in both 2023 and 2024, earning Cy Young votes in the former year, but he’s been barely better than a replacement-level player this season, with a 4.50 ERA in 12 starts. The 27-year-old also isn’t in particularly good recent form, having conceded 10 earned runs in 17 innings across his last three starts. Though he’s prone to the occasional hard hit — and the Rangers tend to rip it — he does have elite chase, strikeout, and walk rates, which is a good fit for Texas’ aggressive plate approach. Kirby has suffered from poor fielding luck, but that’s likely to continue, given that Seattle has been below-average defensively.
Texas Rangers at Seattle Mariners pick, best bet
Best Bet: Over 7.5 (-111)
The hosts’ offense has been extremely cold, and the Rangers’ hasn’t been too much better, but 7.5 is a pretty low line given that neither Kirby nor Rocker is a particularly good pitcher. The Mariners’ bullpen is good but exhausted, given that they haven’t gotten a day off since the All-Star break.
Strong Lean: Randy Arozarena O0.5 Stolen Bases (+320)
Arozarena secured his fifth straight 20-20 season on Tuesday, marking his fourth stolen base in as many games. The 30-year-old Cuban has been solid in the second half, with an .840 OPS and four steals in 13 games. Rocker tends to give up a lot of singles, with a 10th-percentile expected batting average and elite ground ball rate, and he’s been worth negative-three net bases prevented this season.
